This invention relates to a spinner for manufacturing an integrated circuit (IC) device. Particularly it relates to a spinner being capable of removing minute different material particles attached to the surface of a wafer or air bubbles involved in a photoresist layer.
The semiconductor wafers are treated with various processing, during their fabrication, such as a photoresist film formation thereon, developing process of the photoresist layer exposed selectively to ultraviolet light, an etching of silicon oxide layer formed thereon, washing and cleaning to discharge residual treating liquids used, and the like. Recently, the pattern size formed on a semiconductor wafer becomes increasingly fine such as less than one micron to achieve a high packing density on IC substrates. Therefore, it is extremely important to keep the wafers free from defects of micro size, namely in 0.1 micron meter order, such as undesired different particles, dusts, air bubbles in a photoresist films, and so on. These processes are frequently performed in sequential, being desirable to be performed in a single work station without any physical conveyance from station to station. This is because it is very difficult to keep a workpiece away from tiny dusts during the conveyance. In addition, a processing liquid such as etchant used is not permitted to leave any residue on the work piece after the processing.
A spinning method is widely used in semiconductor wafer process to satisfy the above requirements. Particularly, the spinning method contributes to adopt an automated production line for semiconductor devices, because a number of consecutive processes are performed in one spinning work station with several nozzles for respective processing liquids, and the total number of the fabrication steps is reduced.
Furthermore, for a photoresist film formation, the spinning coating is substantially suitable to achieve an even film thickness coated over the wafer with accurate thickness, because the film thickness is relatively easily controlled by controlling the viscosity of photoresist solvent, rotating speed, dispensing speed of the solvent and so on.
The spinner used in a semiconductor device manufacturing, generally, comprises a spinning disk, a spindle, a cup disposed around the rotating disk, and nozzles for dispensing different processing liquids onto the center of the disk sequentially. A workpiece is mounted on the spinning disk, being held by a vacuum chuck or other chucking means and caused to spin at a high speed with the spinning disk, while a liquid chemical to be applied, such as a photoresist solvent, liquid developer, etching liquids, cleaning deionized water, etc., is dispensed onto the workpiece by means of respective nozzles. As a result, the liquid chemical is broadcasted on the surface of the workpiece, to form a layer with thin and uniform thickness by a strong centrifugal force coursed by the high speed spinning.
Tiny particles or alien materials left on the surface of the workpiece or air bubbles of micro size involved in a photoresist layer, causes a serious problem in modern IC devices such as a breakdown or shortage of the circuit formed in the device. In order to eliminate the drawbacks, various methods are adopted to eliminate such micro-particles from associated processing agents. For example, necessary chemicals are purchased under severe specifications for alien material particles mixed therein. The fabrication activity is performed under a strict dust-proof control. Furthermore, fine filters are used to filter the chemical liquids in the fabrication steps. However, since the allowable maximum size of mixed particles of foreign materials or air bubbles is becoming small below one micron, there is a limitation to overcome the problem using the prior art methods described above.